Molding systems, for example hot runner systems, often include components that require the use of various parts having different mechanical and/or physical properties. By way of example only, a molding system may feature a nozzle comprising a nozzle housing and a nozzle tip configured to engage with a gate region of a mold. A heater may supply heat to the nozzle to prevent the resin in the passageway from solidifying. In order to maximize the heat transfer from the heater to the resin, the nozzle housing and tip may be made from a material having a relatively high thermal conductivity such as, but not limited to, a copper alloy.
The nozzle may also include a seal that may be secured to the nozzle tip which forms a seal between the nozzle tip and the gate region of the mold. During operation of the molding system, the nozzle tip may be repeatedly brought in and out of engagement with the mold. This movement may expose the seal to considerable wear/pressure. Additionally, the mold may be relatively cold compared to the nozzle. Accordingly, it is generally desirable to manufacture the seal from a relatively strong material having a relatively low thermal conductivity in order to prevent damage to the seal and to minimize the amount of heat transferred from the nozzle to the mold.
Unfortunately, the different desired properties of the nozzle tip and the seal may require the use of two different materials that may be metallurgically incompatible. For example, many copper alloys and stainless steels are not compatible for welding. Although it may be possible to secure these two materials together using a welding technique, it is very difficult and the resulting connection is generally weak and unreliable. An alternative method of joining the seal to the nozzle may include forming an interference fit or spraying a coating onto the nozzle to form the seal as described in U.S. Pat. No. 6,971,869 (which is fully incorporated herein by reference).
Accordingly, there exists a need for components of an injection molding system to have components (i.e., portions/locations) made of different materials in order to optimize desired material properties at the different portions/locations. There is also a need for a reliable and/or cost-effective process to permanently secure together two or more portions of injection molding system components having different material properties. The present disclosure provides such components and a manufacturing process for them.
It is important to note that the present disclosure is not intended to be limited to a system or method which must satisfy one or more of any stated objects or features of the present disclosure. It is also important to note that the present disclosure is not limited to the preferred, exemplary, or primary embodiment(s) described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present disclosure, which is not to be limited except by the following claims.